1% Cold leg break experiment on PMK-2 Test results and computer code analysis

In the framework of the computer code assessment programme for the VVER-440 type Paks Nuclear Power Plant a 1% cold leg break experiment has been conducted on the PMK-2 integral type test facility. It was followed by calculations using RELAP 5Mod3.1 and ATHLET in order to assess code capabilities. This experiment was started from the nominal operational parameters and it was considered that only the high pressure injection system (HPIS) is available and there is no injection from the safety injection tanks (SIT). This experiment was the repetition of the test measured in 1990 with improved data aquisition system. The first part of this report includes a short description of the facility, the measurement description, the test results including the local void measurement and a short interpretation of the main phenomena. In the second part of the report the analysis performed by the RELAP 5Mod3.1 and ATHLET Mod1.1 Cycle A codes are given.